core/hooks.c

   1 /* hooks.c */
   2
   3 #include "hooks.h"
   4 #include <assert.h>
   5 #include "../lib/array.h"
   6 #include <stdlib.h>
   7
   8 array hooks[HOOKMAX];
   9 unsigned int hookqueuelength;
  10
  11 void inithooks() {
  12   int i;
  13
  14   hookqueuelength=0;
  15   for (i=0;i<HOOKMAX;i++) {
  16     array_init(&(hooks[i]),sizeof(HookCallback));
  17     array_setlim1(&(hooks[i]),2);
  18     array_setlim2(&(hooks[i]),2);
  19   }
  20 }
  21
  22 int registerhook(int hooknum, HookCallback callback) {
  23   int i;
  24   HookCallback *hcbs;
  25
  26   if (hooknum>HOOKMAX)
  27     return 1;
  28
  29   hcbs=(HookCallback *)(hooks[hooknum].content);
  30   for(i=0;i<hooks[hooknum].cursi;i++)
  31     if(hcbs[i]==callback)
  32       return 1;
  33
  34   /* If there is a previously blanked slot, go in there */
  35   for(i=0;i<hooks[hooknum].cursi;i++) {
  36     if(hcbs[i]==NULL) {
  37       hcbs[i]=callback;
  38       return 0;
  39     }
  40   }
  41
  42   i=array_getfreeslot(&hooks[hooknum]);
  43   hcbs=(HookCallback *)(hooks[hooknum].content);
  44   hcbs[i]=callback;
  45
  46   return 0;
  47 }
  48
  49 int deregisterhook(int hooknum, HookCallback callback) {
  50   int i;
  51   HookCallback *hcbs;
  52
  53   if (hooknum>HOOKMAX)
  54     return 1;
  55
  56   hcbs=(HookCallback *)(hooks[hooknum].content);
  57
  58   for(i=0;i<hooks[hooknum].cursi;i++)
  59     if(hcbs[i]==callback) {
  60       /* If there is an ongoing callback, don't actually delete from the
  61        * array in case THIS hook is active */
  62       if (hookqueuelength) {
  63         hcbs[i]=NULL;
  64       } else {
  65         array_delslot(&(hooks[hooknum]),i);
  66       }
  67       return 0;
  68     }
  69
  70   return 1;
  71 }
  72
  73 void triggerhook(int hooknum, void *arg) {
  74   int i;
  75   HookCallback *hcbs;
  76
  77   if (hooknum>HOOKMAX)
  78     return;
  79
  80   hookqueuelength++;
  81   hcbs=(HookCallback *)(hooks[hooknum].content);
  82   for (i=0;i<hooks[hooknum].cursi;i++) {
  83     if (hcbs[i])
  84       (hcbs[i])(hooknum, arg);
  85   }
  86   hookqueuelength--;
  87
  88   if (!hookqueuelength && hooknum!=HOOK_CORE_ENDOFHOOKSQUEUE)
  89     triggerhook(HOOK_CORE_ENDOFHOOKSQUEUE, 0);
  90 }